1. Field of the Invention
The field of the invention is data processing, or, more specifically methods, apparatus, and products for memory management among levels of cache in a memory hierarchy.
2. Description of Related Art
The development of the EDVAC computer system of 1948 is often cited as the beginning of the computer era. Since that time, computer systems have evolved into extremely complicated devices. Today's computers are much more sophisticated than early systems such as the EDVAC. Computer systems typically include a combination of hardware and software components, application programs, operating systems, processors, buses, memory, input/output devices, and so on. As advances in semiconductor processing and computer architecture push the performance of the computer higher and higher, more sophisticated computer software has evolved to take advantage of the higher performance of the hardware, resulting in computer systems today that are much more powerful than just a few years ago.
Computer systems often include a memory hierarchy of caches and main memory. Frequently used information may be stored in the caches for faster access than access from main memory. From time to time, frequently used information, preferably retained in an upper level cache, is evicted from the upper levels of cache due to an eviction of the same information in lower levels of cache causing a longer access time of the information upon a subsequent attempt to access the information.